Unattended devices such as vending machines and utility meters all require periodic servicing. Vending machines need to be serviced on a routine basis, often daily, regardless of their need to be replenished, to collect the cash deposited into the machines and to check their inventories. Many businesses have widely dispersed points of sale that must currently be monitored by employees who periodically travel to these sites to collect receipts and replenish stock. Others depend on customers to report the need to service or maintenance or for information updates. Utility meters have to be read periodically, usually once each month, commonly requiring someone's physical presence at each customer's site. These activities take a significant amount of effort and represent significant expense to the vending machine operators and utility companies. This expense could be greatly reduced by monitoring such devices remotely. Vending machines would need to be serviced only when the inventory actually needs to be replenished, the cash container is nearing capacity or the machine is malfunctioning. Meters could be read without requiring someone's physical presence at the site.
Similarly, the ability to control devices such as thermostats from remote locations would enable building managers and utility companies to manage energy consumption dynamically, thereby moderating demand and substantially reducing the cost to the consumer. Building managers can control the environments and monitor security in clusters of buildings much more efficiently if this can be done remotely. Other devices, such as kitchen appliances and cash registers can also benefit from remote monitoring and control by, for example, enabling manufacturers to monitor malfunctions and schedule repairs or by providing real-time cash-flow information. Appliance manufacturers can improve customer satisfaction by monitoring their installed appliances and dispatch service personnel even before the customer is aware of a problem. Another area in which remote monitoring can be useful is in home and building automation. Such capability would allow travelers or home caretakers to check the temperature in their living rooms and to adjust the heating or air-conditioning accordingly so that it will be comfortable when they arrive home and to open or close drapes or turn on or off lights remotely to give the appearance of an occupied house or to ensure that their house plants receive the correct amount of sun.
Current techniques to provide such remote monitoring and control capabilities typically rely on proprietary radio-frequency networks, often with limited range, thereby still requiring personnel to travel physically to the site, to drive a specially equipped van to within a few hundred yards of the site, or to use private radio frequencies or third-party communication links. Other techniques rely on the presence of a personal computer at the site to provide a communication link between the device of interest and the remote location. In addition, these current techniques require expensive communication hardware, thereby greatly limiting their use in price-sensitive applications. They are also typically tailored to specific applications.